But Mr. Obama’s billboards and visits are integral to Corzine’s strategy against Republican challenger and former US attorney Chris Christie.

“Corzine is trying to push the ties to himself and the president with Democratic voters,” says Patrick Murray, director of polling at the Monmouth University Polling Institute in New Jersey. “This is to get those Democratic voters disenchanted with Corzine and upset with high property taxes to forget about that and vote one for the team, headed by Barack Obama.”

Polls show the strategy is having an impact, says Mr. Murray. In August, a Monmouth/Gannett poll found 17 percent of Democratic voters planned to vote for the Republican Mr. Christie. In the latest poll released Tuesday, that was down to 8 percent.

“More importantly, people who planned not to vote now plan to do so because it is being seen as a referendum on Obama who has an 87 percent approval rating in the state,” says Murray.

Despite the outside help, the race is still expected to be close. Voters are seething over high property taxes, and have put their thumbs down on Corzine proposals to increase gasoline taxes and unload the Turnpike.

One big reason for the political fog in the Jersey race is independent candidate Chris Daggett, a former regional administrator of the Environmental Protection Agency (EPA) who has won the endorsement of the Star-Ledger, the state’s largest paper. In the latest Monmouth/Gannett poll, Mr. Daggett attracts 14 percent of the vote, double his early October showing.

Some of Daggett’s proposals – such as lowering property taxes by adding a sales tax – have gained traction with voters.

However, Murray says he thinks Daggett’s campaign has probably peaked. “If he was able to build on the splash created by his property tax proposal, he would need to be over 20 percent of the vote at this point in time,” he says. “And he does not have the money you need for the most expensive media markets to keep his name out there.”

Some of Daggett’s votes may be the result of voter disgust over the brass-knuckle tactics. “[Corzine] has talked about Christie’s ethics, his weight, and that he did not have a plan to balance the state’s budget. By last week we had a tie race,” says Cliff Zukin, a professor of public policy at the Bloustein School of Planning and Public Policy at Rutgers University.

Corzine, a former Wall Street investment banker who is bankrolling his own campaign, has been spending $1 million a week on advertising since the primary, says Mr. Zukin.

Meanwhile, Christie has been hamstrung by only having $19.5 million in public campaign financing and having to save funds for the last stretch of campaigning.

Obama’s visit will be to Bergen County, across the Hudson River from New York. “Historically, a Republican must win the county to win the state,” says Murray.